Many different flap arrangements for changing the aerodynamic lift generated by an aerodynamic element of an aircraft are known. For example, the Gurney flap originally developed and applied to racing cars by Robert Liebeck and Dan Gurney, protrude vertically into the air flow and cause a stable separation region to form, changing the sectional lift and moment comparable to a traditional flap of much larger size. Gurney flaps have been the inspiration to many aerodynamic control devices. Van Dam, et al. (U.S. Pat. No. 7,028,954) teach micro-electro-mechanical (MEM) translational tabs for enhancing and controlling aerodynamic loading of lifting surfaces mounted near the trailing edge of the wing. One issue created by these devices is that they deploy approximately normal to the surface, and require actuators that are normal to the wing surface, thus limiting their proximity to the wing trailing edge. Schwetzler, et al. (U.S. Pat. No. 6,641,089) teach a movable auxiliary flap that is arranged on a trailing edge of a wing, such that the flap rotates relative to the wing, to move up and down. An undesirable effect is created in the transition states of these flaps, where the state of the flap being perpendicular to the wing surface is not instantaneous and is undesirable.
What is needed is an alternative to conventional aerodynamic control surfaces that are capable of actuation over a wide frequency range, allowing for control of high frequency structural modes as will as low frequency rigid body modes. Further, such control devices are needed that actively control the aeroelastic response without any structural weight penalty and that are simple to command to discrete states without need for a position feedback mechanism. Such a device should be useful for aircraft flight control, turbine engines, helicopters, and wind turbines, thus providing an overall control system that is more robust and fault tolerant than conventional systems.